ClRCU'AR    NO.   63.    SfCOND    EOlTION 


Tnilcd  States  I )epartmen1  oj  Vj^ric-uli urt» 


OF     KN  IOMi'1  ■ 

I        (J      I  |  ■  >  \\    \KI  ' 


KiMIIMil.l.ills    IMI   HOW    lo  (  OM'KOLTI^ 

1  '•      I  .    1 1 .   ( '  I  I  1 1  n  m  ■  i  -  \  O  ' 

In  ( 'hurgt  ol  /.'/•  rding  I 

The  roots  of  vegetable  crop  plants  ol  many  kind 
destructive  influence  of  maggots  which  injure  them  - 
certain  Beasons.  Several  forms  of  injurious  root-maggots  are  recognized, 
but  ol  these  there  arc  three  species  which  are  much  more  destructive 
than  the  others.  The  most  important  are  the  cabbage  maggot  and  the 
imported  onion  maggot,  the  former  a  specific  enemy  of  cabbag<   and 


Kh.   1  -  Seed  i  tii  maRgol    p 

female  from  above;  •/  lur\  a.  froi  Einenl  of  larva:  f.  ana 

I    puparium— all  much  enlarged    antbor'a  111 

other  cole  crops,  the  latter  <>f  the  onion.  A  third  species,  the  Beed-cora 
jot,  attacks  the  sprouting  seeds  of  \»>\\\  onion  and  cote  i  rope  and  of 
a  considerable  variety  of  other  plants,  afterwards  working  into  the  roots 
and  -t.ilks  ben<  ath  the  earth's  surface.  As  the  last-mentioned  in-'  1 1  i- 
nearly  omnipresenl  and  omnivorous,  it   will  receive  tir>t  consideration. 

Those  species  ill  belong  to  the  genus  Pegomya  (  Phorbia  '  of  the  di] 
"ib  family  Anthomyiida?. 

THE  SEED-CORN  MAGGOT. 

/'•'■■•  -  /.:t. 

Vegetable  growers  frequently  find  that  planted  Beed  fails  to  develop, 
and,  on  looking  for  the  cause,  discover  a  small  whit  it  which,  from 

early-observed  occurrence  on  -  '"Trr-Utaic,!  the  51 

got.      In  more  recent  years  it  Ikis  often  l-r.-tL.,- 
t<>  beans,  whence  another  name,  "bean  fly."     Many 


££1 


are  subject  to  damage,  c\bbage,  turnip,  radish,  peas,  onions,  beets,  and 
Beed  potatoes  being  often  much  affected.  This  insect,  which  is  generally 
distributed  in  the  United  States,  is  shown  in  its  different  stages  in  figure  1. 
senibl.es1  thfe  common  bouse  fly.  The  particularly  distinguishing 
characteristic  of  tlit  fly  is  a  io\v  of  short  bristly  hairs  of  nearly  equal  length 
on  the  inside  of  the  posterior  tibia?  or  shanks  of  the  male  (fig.  1,  a). 
The  length  of  the  wing  is  about  one-fifth  and  of  the  body  about  one- 
sixth  of  an  inch.  T')''1^'  is  little  doubt  that  the  insect  is  of  European 
origin  and  that  it  is  increasing  in  destructiveness  in  this  country.1 

In  its  earlier  stages,  also,  the  seed-corn  maggot  resembles  the  house 
fly.  The  maggot  is  footless  and  cylindrical,  presenting  in  profile  the 
appearance  represented  at  <l.  If  measures  about  one-fourth  inch  in 
length  and  about  0.01  inch  in  width.  The  color  varies  from  nearly 
white  to  pale  yellowish.2  The  maggot  transforms  into  a  puparium  (//), 
barrel-shaped,  of  elliptical  outline,  and  pale  brown  in  color,  measuring 
about  0.15  inch  in  length  and  0.05  inch  in  diameter. 

Indications  are  that  there  are  several  generations  of  this  species 
annually,  one  developing  in  the  North  in  June  from  seedlings,  and  later 
ones  from  roots,  dead  or  dying  plants,  and  other  refuse.3 

METHODS   OK  CONTROL. 

Owing  to  the  difficulty  of  destroying  root-maggots  and  other  subter- 
ranean pests  and  the  cost  of  chemicals  for  the  purpose,  growers  depend 
largely  upon  methods  of  prevention.  To  be  thoroughly  effective  these 
methods  should  be  employed  before  the  insect's  eggs  are  laid. 

Sand  and  kerosene. — A  common  method  for  deterring  the  parent  Hies 
from  depositing  their  eggs  consists  in  placing  sand  soaked  in  kerosene — 
a  cupful  to  a  bucket  of  dry  sand — at  the  base  of  the  plants,  along  the 
rows.  This  mixture  will  also  kill  young  maggots  that  might  attempt  to 
work  through  it. 

Carbolic-acid  emulsion.  —  For  all  three  forms  of  root-maggots  which 
we  are  considering,  a  carbolized  form  of  kerosene  emulsion  is  effective. 
This  is  prepared  by  adding  to  1  pound  of  soap  boiled  in  1  gallon  of 
water,  one-half  gallon  of  crude  carbolic  acid,  and  diluting  the  whole 
with  from  35  to  50  parts  of  water.4  This  mixture  is  applied  about  the 
stalks  of  the  plants  affected.  It  is  best  t«>  use  it  a  day  or  two  after  the 
plants  are  up,  or  are  transplanted,  and  repeat  every  week  or  ten  days 
until  about  the  third  week  in  May,  in  the  North.  Farther  south  thee 
applications  must  be  made  earlier  in  the  season. 

'A  more  extended  notice  is  furnished  in  Bui.  33,  n.  s.,  Div.  Hut.,  pp.  84-92. 

-In  all  material  examined  there  are  only  <>  or  7  cephalic  spiracles  (fig.  1.  g), 
whereas  in  the  other  root-maggots  here  considered  there  are  11  or  more. 

'There  i^  evidence  that  another  maggol  has  been  confused  with  this  species. 

'The  mixture  is  effected  according  to  directions  furnished  in  Farmers'  Bulletin 
1l'7,  p.  22  (1903  ed.),  which  will  be  furnished  on  application. 


• 

The  us'  of  mineral  fertilizer*. — Mini  •  Ful  us  ■'■ 

rents,  particularly    when  employed  jubI       '  ftern  Bhowei   has 

thoroughly  wet  the  ground.  The  principal  fertilizers  for  this  purpose  are 
kainit,  nitrate  ol  soda,  and  sulphate  ori'h  ly  be 

used  as  top  dressings  before  planting;  orj  il  n'pt  employed  tiniil  after- 
wards, they  Bhould  be  applied  as  nearlj  i-  possible  to  the  roots,  the 
earth  being  turned  away  from  the  plants  foi  thya  purpose.  These  Ferti- 
lizers possess  the  advantage  ol  acting  also  timulanl  to  plant 
growth,  thereby  facilitating  recuperation  from  root-ma^gol  attack.1 

Danger  from  ««  of  organic  fertilizers. — Stable  manure  and  organic 
fertilizers  are  apl  t<>  induce  infestation,  Bin<  e  the  Bpecies  under  consider- 
ation is  well  known  to  develop  in  excremenl  and  other  decomposing 
material.  Numerous  instances  of  this  have  come  to  the  writer's  knowl- 
edge during  recent  years.  It  is  advisable,  therefore,  to  avoid  tin-  u 
manure,  rotted  leaves,  or  other  organic  fertilizers,  and  to  avoid  planting 
in  fields  in  which  there  have  been  infested  or  diseased  plants. 

Hand  methods.— As  Boon  as  Beed  fails  to  appear  at  the  proper  time  or 
the  plants  -how  Bigns  of  wilting  and  maggots  are  found  to  be  present, 
eed  may  be  hoed  out  or  the  injured  plants  pulled  and  destroyed, 
together  with  the  young  maggots. 

Most  of  the  methods  mentioned  above  have  been  used  with  success 
againsl  onion  maggots  and  other  root-feeding  Bpecies,  and  are  all  thai 
is  required  in  many  cases  of  ordinary  infestation  of  vegetable  roots. 

THE  CABBAGE  MAGGOT. 
/'/  gomya  braasit  a  Bi  >uch< 

Cabbage  and  related  cruciferous  crop  plant-  frequently  Buffer  Bevere 
injury  from  the  attack  of  the  cabbage  maggot.  Young  plants  are  most 
seriously  affected,  the  maggots  eroding  the  outer  Burface  and  boring 
into  the  interior  of  the  roots,  devouring  the  tender  rootlet-  ami 
frequently  penetrating  into  the  lower  portion  of  the  .-talk. 

This  insect,  known  also  as  the  radish  maggot,  is  an  imported  pest, 
ami  was  firsl  noticed  ruining  cabbage,  cauliflower, and  similar  plantain 
New  York  State  aboul  half  a  century  u'".     It  doc-  mosl  Berious  injury 

throughout  the  northern  tier  of    State-  and  Canada,  attacking  all  tonus 

of  crucifers,  whether  wild  or  cultivated.     In  thai  region  it  is  the  cause 

of  more  or  less  1"--  to  these  crops  year  alter  year,  hut  as  with  other 

active  inset.-,  it  is  much  more  abundant  in  some  Beasons  than  in 

others.     Since  1902  it  has  not  only  been  exceedingly  destructive,  but 


1  It  is  frequently  neceesarj  to  nee  these  fertilizers  in  large  qoantitii  -.  In  cab- 
bage ticMs  a  Fertilizer  ol  the  proper  composition  i-  applied  before  planting  at  the 
ran'  of  1,000  i"  1,500  pounds  to  an  acre.     After  the  plants  h  owth, 

a  top  dressing  ol  100  pounds  <>i  nitrate  ol  soda  and  200  pounds  superphosphate 
is  added.  When  the  heads  aie  beginning  to  develop,  a  third  application  ol 
aboul  800  pounds  ol  nitrate  ol  soda  n>  the  acre  is  often  desirable.  I  "i  details 
consult  Voorhees's  "Fertilizers." 


has  increased   in  injuriousness  from  year  to  year.     Frequently  entire 
crops  over  considerable  areas  are  completely  destroyed. 

Two  or  three  generations  of  this  maggot  are  indicated  in  the  Northern 
States,  and  perhaps  four  or  five  in  the  South. 

METHODS   OP   CONTROL. 

Since  this  species  also  is  a  root-feeder,  the  remedies  prescribed  for  the 
seed-corn  maggot  are  applicable.  In  addition  there  are  certain  prevent- 
ive and  other  measures  for  its  destruction  that  have  been  found  success- 
ful, their  use  being  justified  by  the  great  value  of  cabbage  plants. 

Carbolic-acid  emulsion,  prepared  as  prescribed  on  page  2,  and  diluted 
about  3o  times,  is  particularly  applicable  when  this  maggot  occurs  on 
radish  and  other  plants  than  cabbage  and  cauliflower. 

Hand  picking,  although  laborious,  has  the  merit  of  being  effective, 
and  is  practiced  with  considerable  success  by  extensive  cabbage  grow- 
ers, although  not  practicable  on  radish  and  similar  crops.  It  consists 
in  pulling  up  the  young  cabbage  or  cauliflower  plants,  examining  the 
roots  for  eggs  and  maggots,  and  either  destroying  the  eggs  and  maggots 
by  crushing  with  the  hand  or  by  washing  the  roots  in  a  strong  solution  of 
soap  and  then  replanting.  In  most  cases  the  plants  show  no  ill  effects 
from  this  treatment  after  two  or  three  weeks  have  elapsed.  By  looking 
closely,  the  minute  white  eggs  may  be  seen  about  the  stalks  of  young 
cabbages,  and  if  the  earth  be  raked  away  so  as  to  expose  the  eggs  to 
the  sun  these  will  dry  up,  thus  preventing  the  maggots  from  hatching. 
Afterwards  the  plants  should  be  hilled. 

Methods  of  cultivation. — Experience  shows  that  comparatively  little 
is  to  be  expected  from  various  farming  methods  which  are  sometimes 
perfect  safegards  against  other  insects.  Whatever  might  be  advised  and 
found  successful  on  one  farm  might,  for  one  or  more  reasons,  be  found 
ineffective  on  another. 

By  keeping  the  soil  well  hilled  around  the  plants  the  cabbage  develops 
more  roots,  thus  affording  more  food  for  the  maggots  and  still  leaving 
enough  roots  to  strengthen  the  plant  itself. 

Crop  rotation  should  be  followed  with  any  plants  other  than  crucifers 
or  onions.  Witb  these  latter  it  is  inadvisable,  as  the  same  atmospheric 
or  other  conditions  which  induce  injury  by  the  cabbage  maggot  seem  to 
operate  in  increasing  the  numbers  of  the  onion  pest,  which  has  a  similar 
distribution. 

Fall  plowing  is  advisable. 

Crop  remnants  of  all  crucifers,  and  particularly  cabbage  stumps,  should 
be  removed  and  destroyed,  especially  early  in  the  season.  Late  in  the 
fall  a  less  number  of  maggots  would  be  destroyed  in  this  way,  but  it  is 
always  a  desirable  method  for  the  protection  of  the  crop  against  other 
pests  which  harbor  in  the  old  stalks  or  feed  on  the  new  leaves  in  early 
winter,  to  appear  the  next  spring. 


\\ 


/""'-  "'i'1""1   •','""1   each   plant,  ha*   often   I Ivi 

remedy,  bul  those  who  have  tried  ii  are  almost  equally  divided 
efficacy.     ''  '8  well  worth  further  experimenl   where  the  gas  limi  i  in 
^  obtained  fresh  without  difficulty.     It  maj  frequently  I-  had  for  the 
ci  »s1  "I  carl  ing. 

The  bisulphide!  carl treatment.— In  i  ed  paper  cards,  which 

m,l  presently  be  described,  or  other  preventive  methods  here  given  are 
""'  employed,  and  the  ins<  real  numbers  al  the  roott 

cabbage,  bisulphid  of  carl may  be  used,     ttshould  be  applied  b 

""'  r""'  By8tera  "itl,  a  Bpecial  injector  or  Byringe,1  taking  i  are  thai  the 
application  i-  nol  made  di- 
rectly i"  tin-  pi  inta  as  it  i-  \  .  . 
wvx  likely  to  kill  them.  A 
hole  is  made  a  little  distance 
(3  ><v  i  inches)  from  the 
plant,  and  the  injector  in- 
serted at  an  angle,  a-  -I  i«  i\\  n 
in  ii*.'.  2.  After  injecting  the 
liquid  the  instrument  should 
'"'  withdrawn  and   the  hole 

closed    by    packing   it    down 

"iili  the  foot.     From  a  tea- 

Bpoonful  toa  tablespoonful  to 

each  young  plant,  ami  a  sin- 
gle application,  is  generally 

sufficient. 

Tarred  papt  >■  cards. — The 

use  <>t  disks  <>r  pads  .,t  tarn  .1 

paper  for  the   protection   n\ 

cabbage  againsl   the  oviposition  of  the  ily  was  perfected  in  1889  by  Mr 

W  H.  Goff,  who  describes  his  cards  and  the  manner  of  cutting  them  as 

Follows: 

''''"• '''"'V"'"';1"  !V  hexa«onaJ  •"'"'  in  order  to  better  ec mi» 

II1"  material,  and  a  thmner  grade  oi  tarred  papei  than  th, |„1;UV  ,„„„„„  feM 

';  '"'"'•  ;W"  ";,;',  >cheaPer,bu<  bein  lexible,  the  cards  made  f, 

"  are  more  readilj  placed  about  the  plant  without  being  torn 

blade  ot  the  tool,  whirl,  should   be  made  ,,„,-,  blackamith    is 

f0r froo'aband  bent  in  the  for f  a  half  hexagon,  and  then  taking 

™  :;,:",,•  ^  "••  ,!ache8  near,y  to  th«  ''"■"«■'•  -  shown  in  fig.  5.     The  part  mak- 
ng   I,,  star-shaped  col  i,  formed  from  a  separate  piece  ol  steel,  so  attached  to 

U',,:'""  ':,:i,'""ak',  :"'' J"""  with  ,'"'  b,ade-    Thelatte,  is  beveled  fr 

^  all  around,  so  that  by  re ving  the  part  making!  ihaped  cnl 

'he^g*  may  be  ground  on  a  [,  is  important  that  the  angles  in  the 

blade  be  made  perfect,  and  that  its  outlh  ,,.,  half  hexagon. 

•What  is  known  as  the  McGowen  injector,  formerly  man,, factnred  at  III 
v  ^   •  l,,u  no  longer  for  sale,  has  proved  mosl  successful. 


tor  ii 


To  H6e  tlic  tool,  place  the  tarred  paper  on  the  cud  <n'  a  section  of  a  log  or 
piece  of  timber  and  firsi  cut  the  lower  edge  into  notches,  as  indicated  in  fig.  4, 
using  only  one  angle  of  the  tool.  Then  commence  at  the  left  side,  and  place  the 
blade  as  indicated  by  the  dotted  lines,  and  strike  at  the  end  of  the  handle  with 
a  light  mallet,  and  a  complete  card  is  made.  Continue  in  this  manner  a 
the  paper.  The  first  cut  of  every  alternate  course  "ill  make  an  imperfect  card, 
and  the  last  cut  in  any  course  may  be  imperfect,  hut  the  other  cuts  will  make 
perfect  cards  if  the  tool  is  correctly  made  and  properly  used. 

The  cards  should  be  placed  about  the  plants  at  the  time  of  transplanting.     To 
place  the  card,  bend  it  slightly,  to  open  the  slit,  then  slip  it  on  the  center,  the 
stem  entering  the  slit,  after  which  spread  the  card  out  flat,  and  press  the  points 
formed    by  the  star-shaped   cut   snugly 
around  the  stem. 

A  Wisconsin  grower  protected  7,000 
plants  and  secured  a  splendid  crop,  while 
unprotected  plants  nearby  would  have 
been  a  complete  failure  if  the  maggots 
hail  not  been  picked  off  by  hand.  Others 
have  reported  similar  success.  One  re- 
ported having  lost  only  25  plants  out  of 
10,000  to  15,000  that  he  protected  with 
the  cards,  where  ordinarily  he  would 
have  lost  from  7~>  to  !hi  per  cent  of  the 
crop. 


I 


>< 


Fig  3.  -Tarred  paper  card  in 
outline,  one-half  -i/'-  I  after 

OofT). 


Fro.  4.— Showing  how  tool  is  used,  dotted  line 
indicating  position  of  edge  of  tool  (after 

Cioff). 


FlO.  5. -Tool 
for  cutting 
cards,  about 
one-fourth 
size  after 
(Jofl 


The  tarred  ranis  arc  applicable  to 
cabbage  ami  cauliflower  only,  but  it  is  claimed  by  those 

who  have  employed  them 

that  they  are  cheaper, 
more  practicable,  and 
more  efficient  than  any- 
thing else  yet  devised  for 
preventing  the  ravages  of 
the  cabbage  maggot. 
Success  in  using  them  is 
dependent  upon  their  be- 
ing properly  applied,  io  fit  tightly,  so  that  the  rly  is  unable  to  obtain 
access  to  the  stem  for  the  deposition  of  her  eggs.  Cards  must  be  re- 
newed and  their  use  continued  for  each  iimL'L'ot  year  to  be  effective.1 


THE  IMPORTED  ONION  MAGGOT. 
Pegomya  cepetorum  Meade.)2 

The  name  "imported  onion  maggot'"  is  used  for  this  insect  because 
there   are    other  onion-feeding   maggots   in   addition   to  the   seed-corn 

1  A  Wisconsin  firm  has  used  as  many  as  20,000  of  these  cards  a  year,  and  esti- 
mates the  cost  of  material  and  labor  at  about  $1  for  the  protection  of  I.ikmi 
plants.     This  shows  its  practicability  on  a  large  scale. 

-This  species  is  commonly  referred  to  in  literature  as  Anthomyia  and  Phorbia 
ceparum  Bouche.  According  to  Mr.  Coquillett,  it  is  difficult  to  decide,  from  the 
description  of  the  adults,  whether  or  not  1'ouche's  and  Meade's  species  are 
identical. 


jot.     1 1-  injury,  which  constitub    the  mewl  impurtanl  di  iwba< 

tli"'  culture  of  onions,  ie   mplished  bj  tin-  i  onsumption  of  th<   bulb, 

inducing  Bubsequenl  d<  <  aj  ol  th< 
quenl  destrui  i  ion. 

The  il>  and  th(  emhle  preen  din 

avert)  -  a   little  larger.     The  length  ol  the  fly's  bodj    ie    tboul 

thre<     ixteenths  and  the  wing  ex]  irly  thn  I  an  inch. 

The  male  i>  graj  with  black  bristles  and  hairs     it  has  a  white  face  with 
black  hairs,  and  there  are  three  dark  lines  on  the  body  between  the  v 
:tii<  1  a  i"\\  ol  black  spots  on  the  abdomen.     The  female  i^  a  little  the 
r,  and  inclined  t"  dark  yellowish,  with  d  pale  yellowi 

As  in  the  case  of  the  cabbu  two  or  three  generation 

evidently  the  rule  in  the  V  >r1  h. 

REMEDll  S. 

The  methods  of  control  prescribed  for  the  Beed-corn  maggol  an 
quently  aboul  all  that  are  necess  n?   foi  this  3p<  ciee       In  < 
infestation  the  bisulphid  of  carbon  treatment,  discussed  on  pa 
also  other  remedies  advised  for  the  cabbage  maggot,  are  useful,  with 
the  exception  "I  the  tarred  cards,  which  can  nol  be  conveniently  nor 
economically  used  on  union.     The  flies  are  probably  attracted  to  old 
onion    beds    and    t<>  crop    remnants;    hence    'Iran   field   methods   are 
advisable. 

Note  — This  circular  lias  been  prepared  to  facilitate  •  orr<  Bpondi 
due  to  the  fact  that  the  three  root-maggots  mentioned  herein  have  I"  i  o 
extremely  injurious  during  recent  years.  A  monographic  account,  which 
has  been  of  Bervice  in  the  preparation  of  this  circular,  was  published  in 
1894  i>.\  Prof.  M.  V.  Slingerland  (Bui.  78,  Cornell  Univ.  Agl.Exp.  Sta., 
pp.   181-577).      It  is  now  out  of  print. 

Approved  : 

.1  w:i>  Wilson, 

n.  en  tary. 

Washington,  D.  C.    February  VJ    1906. 

O 


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DOCUMENT  ^SISiwacEuawB,; 


